Sometimes irregularities make materials much stronger, sometimes much weaker. Sometimes “fault lines” can be benificial, because they allow the material to be ductile, which you want. Like the ductility of steel, IIRC, comes from irregularities in the lattice structure which are moved around as the material deforms.
And in that deformation (of a metal or other crystal), you both create the discontinuities (esp. dislocations) that increase strength while also introducing brittleness (work hardening). But the highest strength you can get with this kind of process is still not as high as you’d get from a defect free crystal, such as a monocrystalline whisker.
And in that deformation (of a metal or other crystal), you both create the discontinuities (esp. dislocations) that increase strength while also introducing brittleness (work hardening). But the highest strength you can get with this kind of process is still not as high as you’d get from a defect free crystal, such as a monocrystalline whisker.